Merge release-20201130.0-67-gf6cb96bd5 (automated)

6 files changed, 57 insertions, 14 deletions

diff --git a/pkg/flipcall/flipcall_amd64_state_autogen.go b/pkg/flipcall/flipcall_amd64_state_autogen.go
new file mode 100644
index 000000000..0e03c2a65
--- /dev/null
+++ b/pkg/flipcall/flipcall_amd64_state_autogen.go
@@ -0,0 +1,3 @@
+// automatically generated by stateify.
+
+package flipcall
diff --git a/pkg/flipcall/flipcall_arm64_state_autogen.go b/pkg/flipcall/flipcall_arm64_state_autogen.go
new file mode 100644
index 000000000..e0d1275c8
--- /dev/null
+++ b/pkg/flipcall/flipcall_arm64_state_autogen.go
@@ -0,0 +1,5 @@
+// automatically generated by stateify.
+
+// +build arm64
+
+package flipcall
diff --git a/pkg/flipcall/packet_window_mmap.go b/pkg/flipcall/packet_window_mmap_amd64.go
index 869183b11..869183b11 100644
--- a/pkg/flipcall/packet_window_mmap.go
+++ b/pkg/flipcall/packet_window_mmap_amd64.go
diff --git a/pkg/flipcall/packet_window_mmap_arm64.go b/pkg/flipcall/packet_window_mmap_arm64.go
new file mode 100644
index 000000000..b9c9c44f6
--- /dev/null
+++ b/pkg/flipcall/packet_window_mmap_arm64.go
@@ -0,0 +1,27 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build arm64
+
+package flipcall
+
+import (
+	"syscall"
+)
+
+// Return a memory mapping of the pwd in memory that can be shared outside the sandbox.
+func packetWindowMmap(pwd PacketWindowDescriptor) (uintptr, syscall.Errno) {
+	m, _, err := syscall.RawSyscall6(syscall.SYS_MMAP, 0, uintptr(pwd.Length), syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_SHARED, uintptr(pwd.FD), uintptr(pwd.Offset))
+	return m, err
+}
diff --git a/pkg/tcpip/header/udp.go b/pkg/tcpip/header/udp.go
index 98bdd29db..a6d4fcd59 100644
--- a/pkg/tcpip/header/udp.go
+++ b/pkg/tcpip/header/udp.go
@@ -36,10 +36,10 @@ const (
 // UDPFields contains the fields of a UDP packet. It is used to describe the
 // fields of a packet that needs to be encoded.
 type UDPFields struct {
-	// SrcPort is the "source port" field of a UDP packet.
+	// SrcPort is the "Source Port" field of a UDP packet.
 	SrcPort uint16
 
-	// DstPort is the "destination port" field of a UDP packet.
+	// DstPort is the "Destination Port" field of a UDP packet.
 	DstPort uint16
 
 	// Length is the "length" field of a UDP packet.
@@ -64,52 +64,57 @@ const (
 	UDPProtocolNumber tcpip.TransportProtocolNumber = 17
 )
 
-// SourcePort returns the "source port" field of the udp header.
+// SourcePort returns the "Source Port" field of the UDP header.
 func (b UDP) SourcePort() uint16 {
 	return binary.BigEndian.Uint16(b[udpSrcPort:])
 }
 
-// DestinationPort returns the "destination port" field of the udp header.
+// DestinationPort returns the "Destination Port" field of the UDP header.
 func (b UDP) DestinationPort() uint16 {
 	return binary.BigEndian.Uint16(b[udpDstPort:])
 }
 
-// Length returns the "length" field of the udp header.
+// Length returns the "Length" field of the UDP header.
 func (b UDP) Length() uint16 {
 	return binary.BigEndian.Uint16(b[udpLength:])
 }
 
 // Payload returns the data contained in the UDP datagram.
 func (b UDP) Payload() []byte {
-	return b[UDPMinimumSize:]
+	return b[:b.Length()][UDPMinimumSize:]
 }
 
-// Checksum returns the "checksum" field of the udp header.
+// Checksum returns the "checksum" field of the UDP header.
 func (b UDP) Checksum() uint16 {
 	return binary.BigEndian.Uint16(b[udpChecksum:])
 }
 
-// SetSourcePort sets the "source port" field of the udp header.
+// SetSourcePort sets the "source port" field of the UDP header.
 func (b UDP) SetSourcePort(port uint16) {
 	binary.BigEndian.PutUint16(b[udpSrcPort:], port)
 }
 
-// SetDestinationPort sets the "destination port" field of the udp header.
+// SetDestinationPort sets the "destination port" field of the UDP header.
 func (b UDP) SetDestinationPort(port uint16) {
 	binary.BigEndian.PutUint16(b[udpDstPort:], port)
 }
 
-// SetChecksum sets the "checksum" field of the udp header.
+// SetChecksum sets the "checksum" field of the UDP header.
 func (b UDP) SetChecksum(checksum uint16) {
 	binary.BigEndian.PutUint16(b[udpChecksum:], checksum)
 }
 
-// SetLength sets the "length" field of the udp header.
+// SetLength sets the "length" field of the UDP header.
 func (b UDP) SetLength(length uint16) {
 	binary.BigEndian.PutUint16(b[udpLength:], length)
 }
 
-// CalculateChecksum calculates the checksum of the udp packet, given the
+// PayloadLength returns the length of the payload following the UDP header.
+func (b UDP) PayloadLength() uint16 {
+	return b.Length() - UDPMinimumSize
+}
+
+// CalculateChecksum calculates the checksum of the UDP packet, given the
 // checksum of the network-layer pseudo-header and the checksum of the payload.
 func (b UDP) CalculateChecksum(partialChecksum uint16) uint16 {
 	// Calculate the rest of the checksum.
diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go
index 5043e7aa5..ee1bb29f8 100644
--- a/pkg/tcpip/transport/udp/endpoint.go
+++ b/pkg/tcpip/transport/udp/endpoint.go
@@ -1267,7 +1267,6 @@ func verifyChecksum(hdr header.UDP, pkt *stack.PacketBuffer) bool {
 // HandlePacket is called by the stack when new packets arrive to this transport
 // endpoint.
 func (e *endpoint) HandlePacket(id stack.TransportEndpointID, pkt *stack.PacketBuffer) {
-	// Get the header then trim it from the view.
 	hdr := header.UDP(pkt.TransportHeader().View())
 	if int(hdr.Length()) > pkt.Data.Size()+header.UDPMinimumSize {
 		// Malformed packet.
@@ -1276,6 +1275,10 @@ func (e *endpoint) HandlePacket(id stack.TransportEndpointID, pkt *stack.PacketB
 		return
 	}
 
+	// TODO(gvisor.dev/issues/5033): We should mirror the Network layer and cap
+	// packets at "Parse" instead of when handling a packet.
+	pkt.Data.CapLength(int(hdr.PayloadLength()))
+
 	if !verifyChecksum(hdr, pkt) {
 		// Checksum Error.
 		e.stack.Stats().UDP.ChecksumErrors.Increment()
@@ -1309,7 +1312,7 @@ func (e *endpoint) HandlePacket(id stack.TransportEndpointID, pkt *stack.PacketB
 		senderAddress: tcpip.FullAddress{
 			NIC:  pkt.NICID,
 			Addr: id.RemoteAddress,
-			Port: header.UDP(hdr).SourcePort(),
+			Port: hdr.SourcePort(),
 		},
 	}
 	packet.data = pkt.Data